content: /*
   * Copyright 2016-present David Karnok
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package hu.akarnokd.rxjava3.debug.validator;
  
  import hu.akarnokd.rxjava3.functions.PlainConsumer;
  import io.reactivex.rxjava3.core.*;
  import io.reactivex.rxjava3.disposables.Disposable;
  
  /**
   * Validates a Single.
   * @param <T> the value type
   * @since 0.17.4
   */
  final class SingleValidator<T> extends Single<T> {
  
      final Single<T> source;
  
      final PlainConsumer<ProtocolNonConformanceException> onViolation;
  
      SingleValidator(Single<T> source, PlainConsumer<ProtocolNonConformanceException> onViolation) {
          this.source = source;
          this.onViolation = onViolation;
      }
  
      @Override
      protected void subscribeActual(SingleObserver<? super T> observer) {
          source.subscribe(new ValidatorConsumer<T>(observer, onViolation));
      }
  
      static final class ValidatorConsumer<T> implements SingleObserver<T>, Disposable {
  
          final SingleObserver<? super T> downstream;
  
          final PlainConsumer<ProtocolNonConformanceException> onViolation;
  
          Disposable upstream;
  
          boolean done;
  
          ValidatorConsumer(SingleObserver<? super T> downstream,
                  PlainConsumer<ProtocolNonConformanceException> onViolation) {
              super();
              this.downstream = downstream;
              this.onViolation = onViolation;
          }
  
          @Override
          public void onSubscribe(Disposable d) {
              if (d == null) {
                  onViolation.accept(new NullOnSubscribeParameterException());
              }
              Disposable u = upstream;
              if (u != null) {
                  onViolation.accept(new MultipleOnSubscribeCallsException());
              }
              upstream = d;
              downstream.onSubscribe(this);
          }
  
          @Override
          public void onSuccess(T t) {
              if (t == null) {
                  onViolation.accept(new NullOnSuccessParameterException());
              }
              if (upstream == null) {
                  onViolation.accept(new OnSubscribeNotCalledException());
              }
              if (done) {
                  onViolation.accept(new OnSuccessAfterTerminationException());
              } else {
                  done = true;
                  downstream.onSuccess(t);
              }
          }
  
          @Override
          public void onError(Throwable e) {
              if (e == null) {
                  onViolation.accept(new NullOnErrorParameterException());
              }
              if (upstream == null) {
                  onViolation.accept(new OnSubscribeNotCalledException(e));
              }
              if (done) {
                  onViolation.accept(new MultipleTerminationsException(e));
              } else {
                  done = true;
                  downstream.onError(e);
              }
          }
  
          @Override
          public void dispose() {
              upstream.dispose();
          }
  
          @Override
          public boolean isDisposed() {
              return upstream.isDisposed();
          }
      }
  }
  